And continuing our World Lead. The Malaysian prime minister announced earlier today that Malaysia Airlines Flight 370 is likely in the southern Indian Ocean and that all on board likely have perished, which pushes the focus underwater now. Signs of possible debris have ramped up over the past few days, but even if any are confirmed to be a part of the plane, that does not necessarily ease the search for the wreckage under water. The U.S. Navy has announced it has requested that a Toad Pinger locator system be moved into the area to help find those flight recorders. It's a listening device put in the water to help find the pings of the recorder, although they stress it's not really useful until you have a debris field. Now, that thing can't be picked up by human ears, but we converted it to an audible signal, and listen to what it sounds like.

(AUDIO CLIP)

SCIUTTO: Now, this is a very difficult search with so many obstacles. So we want to bring in Ian McDonald to help explain. He is a professor of oceanography at Florida State University. Ian, thank you for coming on board. You've given us some maps to look at help project where the possible wreckage could be if the debris that was spotted on March 16th, just a few days ago, could be confirmed as part of the plane. Explain this map that we're looking at with the plotted points down there, the black ones and the red ones. What do we see?

IAN MCDONALD, OCEANOGRAPHY PROFESSOR: Well, the best way to find the location of the crash site is to back calculate from the earliest sighting of wreckage, which occurred on March 16. What you're seeing there what was performed about Dr. Steve Morey at the Center for Ocean Atmospheric Studies. What it shows is the probable pathway from the 8th of March to the 16th of March of some 10,000 objects that were put into the water and tracked with a simulation model called the Hi-Comm (ph) model.

SCIUTTO: Now, when you look at those pieces, because for instance yesterday, you have some of the airplanes that are flying from Australia to fly over this search area. They spotted some debris, then go back the next day, the ship couldn't find them. To give our viewers a sense of how quickly the field of play can change, how much can one piece of floating debris move, say, in a day, in 24 hours?

MCDONALD: Well, the drip trajectory that we see shows a possible movement of between 15 to 125 miles over eight days between the 8th and the 16th. So the good news is that this is a region where there's a lot of rotating ocean currents. Things are not being swept along by a continuously moving flow. They can move a long way, but hopefully they are not moving too far.

SCIUTTO: The French are saying now it's too early to send a submarine to aid in the search, and I suppose part of that reason is that even when you stick listening devices into the water, they can only listen for maybe one or two miles. So you need to zero in on the debris field more. Talk to us through some of the equipment that they would use, at least at the point that you found debris so you can guess more intelligently as to where the actual plane is.

MCDONALD: Well, if they find -- if they hear a ping from the transponder, they will deploy autonomous underwater vehicles, AUVs, which follow preset search patterns. They go down and "mow the lawn" back and forth over an area where they think the wreckage might occur. If they locate the wreckage, then they will come in with ROVs -- these are tethered vehicles that can go down and manipulate the debris field and hopefully recover the black boxes.

SCIUTTO: That's interesting. I've seen some of those images they come back with from the bottom of the ocean. They're not exactly definitive. That takes a bit of art it seems as well.

Let's also talk about the bottom of that ocean because it's such a remote part of the world. You were telling us that it hasn't been mapped yet by oceanographers, right? How does it make it more difficult to search for something like this?

MCDONALD: It has been mapped, but the maps are very coarse resolution. They're nothing like the maps that we have along the coast of the United States, for example. So that means they don't know how irregular the terrain is likely to be. There is the southern Indian ridge in this region, and that's an area where there might even be volcanic debris flows and irregular terrain. It would make the searching very difficult.

So, one of the first jobs is going to try to map the sea floor in this area using SWAT (ph) mapping techniques from surface ships.

SCIUTTO: It's an incredible thought to know that even when you find that debris, really, the work has just begun. Thanks very much to Ian McDonald for joining us.

When we come back, satellites have tracked the plane into one of the most remote areas of the world. But is that enough to rule out the speculation that Flight 370 was sabotaged?

Plus, we're hours away from first daylight when the search will resume. How close are ships now to this area?

(COMMERCIAL BREAK) SCIUTTO: Welcome back to THE LEAD. More now on our World Lead.

Until the black boxes from Flight 370 or even pieces of debris are found, investigators will still be playing something of a guessing game to figure out what ultimately took that plane down. But we did learn some key pieces of information over the weekend that could help shed light on that suspicious turn the plane took just minutes after all communication was lost with air traffic control.

CNN national correspondent Suzanne Malveaux has more.

(BEGIN VIDEOTAPE)

SUZANNE MALVEAUX, CNN NATIONAL CORRESPONDENT: New information is revealed about the final hours of Malaysia Flight 370, giving us more insight into what was happening in the cockpit during the critical moments before the plane went down.

Saturday, March 8th at 12:41 a.m. local time, Malaysia Flight 370 takes off from Kuala Lumpur head to Beijing. The Boeing 777 is carrying 227 passengers and 12 crew on board. Twenty-six minutes into the flight at 1:07 a.m. one of the plane's critical communication system, called ACARS, sends its final information. It measures thousands of pieces of information about the plane and pilots' performance and sends it via satellite.

We now know it shows the plane remained on course for Beijing, contradicting earlier reports that the pilots programmed a change in the cockpit before sending their radio final transmission. A transcript from London's "Telegraph" newspaper reveals there is nothing out of the ordinary in their communications with air traffic control.

At 1:19 a.m., this exchange. "MH-370, please contact Ho Chi Minh City, 120.9. Good night." The co-pilot's response: "All right, good night." At 1:21 a.m., the transponder, which identifies the plane to civilian radar, stops communicating. Critical information, like the plane's flight number, height, speed, and heading, are all cut off. This happens at the same time the plane is supposed to check in with air traffic control in Vietnam. Then, between 1:21 and 1:28 a.m., a Malaysian military radar shows the plane making a sharp turn over the South China Sea then changing altitude as it heads towards the Strait of Malacca dipping as low as 12,000 feet. The plane then disappeared from all radar.

At 2:40 a.m., Malaysia Airlines tries to contact the missing flight. By 3:45 a.m. the airline issues a code red alert declaring a crisis. At 6:30 a.m., Flight 370 is due to land in Beijing. At 8:11 a.m., more than seven hours after takeoff, the final ping from the plane, a commercial satellite orbiting more than 22,000 miles above earth receives the plane's final so-called handshake. Now, a new analysis puts Malaysia Flight 370 here, far from any landing site in the South Indian Ocean. Suzanne Malveaux, CNN, Washington.

(END VIDEOTAPE) SCIUTTO: Suzanne Malveaux, thank you. Given this new information, can investigators rule out the possibility that the plane was in some way sabotaged or hijacked? Joining me now live is CNN aviation analyst, Jim Tilmon. He is also a retired pilot and Dr. Alan Diehl, a former NTSB air safety investigator and author of the "Air Safety Investigators Using Science To Save Lives One Crash At A Time."

Jim, I want to begin with you because we really have two bits of new information now. One as Suzanne was reporting the idea that the flight was not pre-programmed to make this turn, perhaps it was responding to something and also now this new satellite data that shows a long, slow path into the South Indian Ocean.

I know speaking to you before you've been convinced that something criminal took place to divert this plane off its path. Given what we know now, though, has this changed your analysis of the situation?

JIM TILMON, CNN AVIATION ANALYST: Jim, very little has changed. I mean, the most important has changed, if there is one, is the information about what the U.K. was able to come up with about position of the aircraft and just before it hit the water. But that's just one analysis. We really have a whole lot to analyze before we come up with anything conclusive.

For example, exactly how long did it take to go from 35,000 to 12,000 feet? Why 12,000 feet? What was the idea there? If it went down as rapidly as I think it did, they probably would have had to have used a speed brake to do that. Once they got to 12,000 feet, was the crew able to respond properly? If they were, they would relax that speed brake, which I think they had to do if they were going to fly for another several hours.

And flying for another several hours incapacitated? There are lots of questions left, Jim and I'm delighted we got what they did, but there's so much more.

SCIUTTO: Certainly questions unanswered. I wonder Al, former NTSB air safety investigator, you looked into cases like this previous cases, does this information change the game for you at all?

ALAN DIEHL, FORMER NTSB AIR SAFETY INSVESTIGATOR: Not totally. Obviously everything must still be on the table but it does follow a couple of previous scenarios that turned out to be accidents. We can talk a little bit about them. Again, I'm just an aviation psychologist that happens to have an airplane pilot's license. I don't have a crystal ball. I'm not saying this did have happen, but one possibility is what I call is what I call a "Cairo gate" scenario.

They are in Cairo at the gate, another 777 belonging to Egypt there. Pilots who are in the cockpit when a fire breaks out in their oxygen system. The first officer goes out and gets the passengers off the aircraft. The captain tries to fight the fire with the fire bottle and within minutes it burns a hole in the fuselage. Not a big problem if you're sitting on the ground.

But if that were to happen, that scenario -- and I'm not saying it did, but if that were to happen at 35,000 feet, I think Captain Tilmon would say, that's a double whammy and I'm not sure anybody could have handled that compound emergency in reality.

SCIUTTO: NO question, Jim, one thing we've all struggled with here. If it was an accident on that plane even a fast moving accident, how do we account for the fact that the crew never sends a mayday signal to indicate to the ground that something wrong had happened?

TILMON: I'd like to think that they were so busy they didn't get around to it, but someone asked, you know, how difficult is it to get off a message? Well, the mic button is right under the captain's thumb. Actually he pushes on that and he's talking on the air. I don't think it's difficult to do and it's been a real problem for me as to why they didn't say that. But if it was a really bad situation, then, of course, obviously they would not have had time to do anything about it, but the airplane would not have been able to fly successfully for the next few hours and if it wasn't that bad, they had ample opportunity to make a distress call. The conundrum really has not changed because of this new information.

SCIUTTO: Well, Al, there have been cases -- and you're great at bringing up past cases to the extent that they can inform us. There have been cases of the Payne Stewart jet flight where crew and the passengers were incapacitated where it flew for a few hours before slamming into the ground. Could that be indicative in this situation?

DIEHL: Well, it certainly is in play right now and there's a better example, Helios, which is a Greek airline flying a 737 out of Cyprus, they had a slow decompression. It took the pilots out. The passengers all passed out. By the way, no cell phone calls and 2-1/2 hours later, jets intercepted. They look in the cockpit and they see a flight attendant flying the aircraft. Now, I'm not saying that happened in Malaysia, but that one fits -- that could be part of the puzzle and I know Captain Tilmon will tell you, if you jerk back on the yoke on the kind of planes that he's flown, you disengage the autopilot.

So those gyrations that the Malaysian radar picked up -- I'm not saying it was a flight attendant, but somebody trying to master aviation 101. Besides, if you had a fire in that cockpit, you would lose most of your instruments like at Swiss Air. This fits some scenarios and we can't discount the fact that they had 400 pounds of ion lithium batteries on board.

SCIUTTO: Jim, just very quickly. I wonder if I can ask, one of the frustrations is that there has been conflicting information coming from Malaysian authorities. Do you look at this new information with skepticism in terms of determining what it means for what brought this plane down?

TILMON: Yes. I have looked at everything with skepticism ever since I found out how poorly this thing was being managed and how many changes we were surprised with. So until I actually see something, show me a piece of wreckage. Give me something that I can physically identify as being the airplane, I'll feel a lot more comfortable about making a full analysis. SCIUTTO: Thank you so much. We're all waiting for hard answers. Thank you so much. Wolf Blitzer will be here to tell us what is going on.

WOLF BLITZER, HOST, CNN'S "THE SITUATION ROOM": The Inmarsat vice president of communications, I spoke to him, said most likely the plane went in the southern part of the Indian Ocean and went into the water there. But he didn't say definitively and when I pressed him, was it 100 percent conclusive, the most he could say was most likely. So we're going to find out why the Malaysian prime minister said that the people are dead while the Inmarsat officials are saying probably but not necessarily 100 percent. So we are looking at that.

SCIUTTO: It's a scary thought and the families are expressing their doubt about it.

BLITZER: Chinese government, too.

SCIUTTO: Coming up, we are going to get close to first daylight when team will resume their search of the Indian Ocean. Next what they are up against in one of the most treacherous patches of oceans in the world. Please stay with us.

(COMMERCIAL BREAK)

SCIUTTO: Welcome back to THE LEAD. And more now on our continuing coverage of the mystery of Flight 370. Hope for survivors may be lost, but the hunt for that plane continues with a new level of certainty today about the approximate search area and just hours to go before daylight. All eyes are on a treacherous part of an ocean that's been called one of the most remote places on the planet.

So I want to bring in Kyung Lah. Now she is live in Perth, Australia where all those planes are taking off. We're just an hour away from those first flights leaving. What is the state of the investigation right now?

KYUNG LAH, CORRESPONDENT: Well, there is this desire and we've heard it all along from the pilots and people on board these planes to bring back the evidence. There was always the uncertainty running through the search teams that the wreckage is out there and now they have the answer. They want to bring the debris back, but first they have to find it. We're expecting the first plane to take off and make the four-hour search down there and search for two hours and they be four- hour flight back. Weather today though, Jim, much worse than it has been. The cloud cover expected to be worst away even higher.

SCIUTTO: Particularly the wind out there I know is a major issue and that's been whipping up in the last couple of days.

LAH: Absolutely. The wind is a big problem. One of the pilots -- a squadron leader of the P-8 did say that the way it looks out there to him is a giant washing machine. So that's what they are going to be looking at today.

SCIUTTO: A giant washing machine, just is about the worst you can imagine. Kyung Lah in Perth, thanks very much.

Make sure to follow the show on Twitter @theleadcnn and heck out our show page at cnn.com/thelead for videos, blogs and extras. You can also subscribe to our magazine on flip board.

That's it for today on THE LEAD. I'm Jim Sciutto. I'm going to turn you over now to Wolf Blitzer who is in "THE SITUATION ROOM."